Alternative Testing Methods For Electronic Assemblies
Authors: Mathias Nowottnick, Andrej Novikov, Dirk Schade, and Bob Sykes Company: University of Rostock and XYZTEC BV Date Published: 10/14/2012
Abstract: Electronic assemblies will be used more and more for harsh environments, e.g. for industrial application, avionic, environmental or automotive use. The common test methods can only give partially information about the demanded characteristics. This includes notably high or low service temperatures, corrosive atmospheres, vibrations or extreme acceleration. An accelerated ageing can be realized today by thermo-cyclic exposure, also in combination with other loading by high temperature or high humidity. In contrast it is usual to apply a shear test at room temperature and with shear rates in the middle range for testing and evaluation of mechanical properties of solder joints. A variation of the shear rate can deliver additional information. Extra slow testing velocities will effect solder creeping, but this needs also a very long testing time. In contrast very high testing velocities are reflective in an increased instantaneous strength, which is important for drop and collision demands. With a special developed impact test it is possible to identify better the characteristics of interfaces, voids or pre-existing damages by cracks. For some samples and defined conditions it is also possible to compare results of the impact test with standard shear tests. Further interesting approaches for alternative mechanical testing of solder properties for high and low temperatures will be also presented in this paper.